1. Field of the Invention
This invention relates to a new and useful improvement in synthesizing crystalline porous chalcogenides, e.g. crystalline silicates or the like, the new crystalline materials synthesized, and to use thereof as catalyst components for organic compound, e.g. hydrocarbon compound, conversion.
More particularly, this invention relates to an improved temperature programmed method for preparing crystalline porous chalcogenides, e.g. ZSM-23, whereby synthesis is facilitated and reproducible and the silicate product exhibits high purity, small, uniform crystal size, improved catalytic activity and stability.
2. Discussion Of Prior Art
Synthesis of crystalline porous chalcogenides, e.g. silicates or like materials, is conventionally accomplished by creating a reaction mixture comprising required components, e.g. organic, seed, sources of alkali metal cations, germanium, silicon, aluminum, phosphorous, boron, etc., and heating the mixture to a crystallization temperature within a prescribed range.
Crystalline silicate ZSM-23, for example, and its conventional preparation, e.g. from a reaction mixture containing pyrrolidine directing agent, are taught by U.S. Pat. No. 4,076,842, the entire disclosure of which is incorporated herein by reference. It has a distinctive X-ray diffraction pattern which identifies it from other known crystalline silicates. Synthesis of crystalline silicate ZSM-23 from a reaction mixture containing hexamethyl-diquaternary ammonium with a saturated or unsaturated C.sub.7 bridge hydrocarbon moiety as directing agent is taught in U.S. Pat. Nos. 4,490,342 and 4,619,820, the entire disclosure of each incorporated herein by reference. The diquaternary used in synthesis of ZSM-23 in the latter patents is shown in U.S. Pat. No. 4,531,012.
Zeolite KZ-1, having the structure of ZSM-23, is shown in Zeolites, 1983, Vol. 3, pages 8-10, to be synthesized from a reaction mixture containing pyrrolidine, 2-aminopropane or dimethylamine, silica, aluminum sulfate and sodium hydroxide. Zeolite ISI-4, having the structure of ZSM-23, is shown in European Patent Application 102,497 to be synthesized from a reaction mixture containing an alkali metal, e.g. sodium or potassium, and/or alkaline earth metal, e.g. calcium, and large amounts of ethylene glycol or monoethanolamine. Both KZ-1 and ISI-4 are taught to be crystallized at a temperature within a single standard range.
U.S. Pat. No. 4,296,083 claims synthesizing zeolites characterized by a Constraint Index of 1 to 12 and an alumina/silica mole ratio of not greater than 0.083 from a specified reaction mixture containing an organic nitrogen-containing cation, depending upon the particular zeolite desired, provided by, for example, an amine identified as being selected from the group consisting of triethylamine, trimethylamine, tripropylamine, ethylenediamine, propanediamine, butanediamine, pentanediamine, hexanediamine, methylamine, ethylamine, propylamine, butylamine, dimethylamine, diethylamine, dipropylamine, benzylamine, aniline, pyridine, piperidine and pyrrolidine.
U.S. Pat. No. 4,112,056 teaches synthesis of ZSM-23 with pyrrolidine directing agent by adding a source of aluminum ions to a silica-rich amorphous reaction mixture at a rate whereby the aluminum ion concentration in the reaction mixture amorphous phase is maintained at steady state during crystallization. U.S. Pat. No. 4,497,786 shows treatment of zeolites, for example ZSM-23, following crystallization by increasing the temperature, e.g. cooking the crystals, to deagglomerate them.
U.S. Pat. No. 4,341,748 shows synthesis of ZSM-5 or ZSM-11 from reaction mixtures comprising, for example, ethanol, ZSM-5 or ZSM-11 seeds, ethanol and seeds, ethanol and ammonimum hydroxide, and ethanol, ammonimum hydroxide and seeds.
U.S. Pat. No. 4,104,151 shows organic compound conversion over catalyst comprising ZSM-23 prepared as in U.S. Pat. No. 4,076,842, above. U.S. Pat. Nos. 4,222,855; 4,575,416 and 4,599,162 teach dewaxing reactions over ZSM-23 catalysts. Aromatics alkylation, e.g. ethylbenzene synthesis, over catalyst comprising, for example, ZSM-23 is demonstrated in U.S. Pat. Nos. 4,547,605 and 4,107,224. ZSM-23 prepared in usual fashion and with an amorphous precipitated silica source of silicon for xylene isomerization is shown in U.S. Pat. No. 4,599,475. A combination process for conversion of olefins to high VI lubes, where the ZSM-23 catalyst component is synthesized from a reaction mixture containing a pure silica, is taught in U.S. Pat. No. 4,524,232.
Other catalystic uses of ZSM-23 include conversion of cumene to acetone and phenol (U.S. Pat. No. 4,490,566), dewaxing (U.S. Pat. Nos. 4,372,839 and 4,428,865), dewaxing hydrocrackate to make lube oil (U.S. Pat. No. 4,414,097), toluene disproportionation (U.S. Pat. No. 4,160,788), selective production of p-substituted benzene (U.S. Pat. No. 4,100,217) and selective production of p-xylene (U.S. Pat. No. 4,049,738).
Applicants know of no prior art teaching synthesizing crystalline silicates or like materials, e.g. ZSM-23, as in the present invention.